We haven't had any more reports of this happening, so it seems this was fixed. If any of you are still experiencing problems please file a support ticket.
Most likely the cause was that the dns servers hosting the domain the game tries to connect to when its connecting to heRO were having issues and not reporting the ip consistently, and since some ISPs cache the ip reported longer than they should that explains why some were having issues for longer times than others. This is something out of our control unfortunately.
If it happens again you can try setting your computer to use opendns or another free dns server and you should be able to get trough that way.